<i>Radumeris tasmaniensis saussure</i> in New Zealand distribution and potential host range

Abstract

The yellow flower wasp (Radumeris tasmaniensis) was first reported in Northland, New Zealand, in February 2000 at three locations, Herekino and Twilight on the west coast and Whareana on the east. Radumeris tasmaniensis is a solitary wasp that occurs extensively in Australia and Papua New Guinea, and is a parastoid of large (>1.5 g) scarab larvae. As the threat to native Scarabaeidae was unknown, MAF Biosecurity commissioned a survey to determine the distribution and potential host range of R. tasmaniensis. A delineation survey using Malaise, attractant, pitfall, and sticky traps conducted over February and March 2001 at 40 sites on both coasts of Northland confirmed that R. tasmaniensis had only established at the three original sites. Parasitised scarab larvae were not detected in a concurrent soil fauna survey. However, circumstantial evidence indicated that larvae of the sand scarab (Pericoptus truncatus), a suitable size for R. tasmaniensis larvae, were the primary hosts. Adult R. tasmaniensis were only observed in dune country, the habitat of the sand scarab and were active during March when the sand scarab larvae were present. African black beetle (Heteronychus arator) reaches pest populations in pasture in Northland and is a potential host. However, it was scarce in dune land and was in the adult stage during March so was not available as a host to R. tasmaniensis.

The yellow flower wasp <i>Radumeris tasmaniensis</i> Saussure (Hymenoptera Scoliidae) potential threat to New Zealand native fauna

“…This study aimed to determine the current distribution of R. tasmaniensis in Northland and identify current and potential scarabaeid hosts of R. tasmaniensis in New Zealand. METHODS The three sites where R. tasmaniensis had been recorded in 2000, were sampled in 2001 to delineate the distribution around these sites (Willoughby et al 2001). Sample sites were established at positions approximately 1, 2 and 5 km in both directions along the coast and inland from each of the three known sites.…”